fix(client): degrade against a node still speaking MNP 1.0

The SPA is served by the hub, so deploying the hub puts this client in front of
every node — including the ones not updated yet. That window is the normal
state for as long as an operator takes, and for a node someone else runs it may
be indefinite. Three controls were broken across it, and the failure mode is
quiet: an unknown message type is logged by the node and never answered, so the
click produces a thirty-second wait ending in a timeout with nothing on screen
to say the node simply cannot do this.

Files' Upload button read `root.writable`, which a 1.0 node does not send — it
says `upload`, the same answer under the older name. The button disappeared on
every un-upgraded node. It reads both now, and still respects an explicit
`writable: false` rather than falling through to the legacy flag.

The per-app folder pickers spoke `app_directories`. Videos, Music and Photos
each had their own message before that and those still work, so the page
chooses by version: an operator on an older node keeps the ability they had.
`video_root` and `audio_root` hold one folder, so several are refused with a
reason rather than stored as the first and silently truncated.

Root management — writable, removable, eject, plug — has no older equivalent to
route to, so the table goes read-only with a line saying why and pointing at
the `meshbay-node root` commands. Chat's two settings are new with nothing
before them and are hidden the same way.

None of this was inferred from a payload's shape: `_checkNodeVersion` already
parsed the node's version and threw it away, and it is kept now. Coupling a
capability to whether some field happens to be present is how a flag flips
because an unrelated payload changed.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011pvMdvLBG92jyhvD5pD6us

1 files changed, 8 insertions, 1 deletions

diff --git a/packages/meshbay-hub/src/meshbay_hub/static/files-app.js b/packages/meshbay-hub/src/meshbay_hub/static/files-app.js
index 6825c8d..a6a3ca4 100644
--- a/packages/meshbay-hub/src/meshbay_hub/static/files-app.js
+++ b/packages/meshbay-hub/src/meshbay_hub/static/files-app.js
@@ -221,7 +221,14 @@ function FilesPanel({
     : subdirs.filter(d => rootState.get(d) && rootState.get(d).available === false);
   const currentRootName = currentPath ? currentPath.split('/')[0] : '';
   const currentRoot = currentRootName ? rootState.get(currentRootName) : null;
-  const currentRootWritable = currentRoot ? currentRoot.writable : false;
+  // `upload` is the same answer under the name a node speaking MNP 1.0 uses;
+  // reading only `writable` there means the Upload button disappears on every
+  // node that has not been upgraded yet, which is most of them on the day the
+  // page ships.
+  const currentRootWritable = currentRoot
+    ? (currentRoot.writable !== undefined ? currentRoot.writable
+                                          : Boolean(currentRoot.upload))
+    : false;
   // A member cannot create a folder at the top of a group: that level is the
   // set of roots, which is the operator's configuration and not a directory on
   // anyone's disk. The node refuses it, so offering it would only produce an